Geographic information systems (GIS) are used to manage many types of information about the earth. Data points representing information such as altitude or plant growth can be mapped using global positioning system data to create layers in a GIS. GIS can even be used to analyze areas that are covered with water, such as aquatic environments. GIS can get input from many different sources, including aerial photographs and acoustic sounders. In this manner, data can be organized and mapped to specific areas of the planet.
Depth finders/acoustic sounders mounted on watercraft are often used by scientists and sportsmen/women for various purposes. For example, a scientist may want to detect and measure aquatic plant growth in a lake. For another example, an angler may want to find fish in a river or identify trends in each item located by sounding. A typical depth finder display shows the depth of the water beneath the boat and possibly information regarding what is to the sides of the boat. This information is only displayed for a short period of time, as the display is constantly being updated with new data. While depth finder data can be used to create a GIS layer, the data collected by a depth finder depends on the path taken by the boat. This data is not easily entered into GIS software that stores data according to absolute coordinates.